Publications

2016
Lidia Mínguez-Alarcón, Russ Hauser, and Audrey J Gaskins. 2016. “Effects of bisphenol A on male and couple reproductive health: a review.” Fertil Steril, 106, 4, Pp. 864-70.Abstract
Bisphenol A (BPA) is a ubiquitous environmental toxicant with endocrine-disrupting properties and is suspected to affect human reproduction. The objective of this review was to summarize the potential effects of male exposure to BPA on markers of testicular function and couple reproductive outcomes. Five epidemiologic studies on BPA and reproductive hormones all found significant associations with at least one reproductive hormone; however, no consistent relationships were observed across studies. Six epidemiologic studies evaluated the relation between BPA and semen parameters, and although the majority reported negative associations with various parameters, there were few consistent trends across studies. Finally, three epidemiologic studies examined BPA and couple reproductive outcomes, and only one found an association. Overall, the evidence supporting an association between BPA exposure and adverse male reproductive health outcomes in humans remains limited and inconclusive. Reasons for the discrepancies in results could include, but are not limited to, differences in study populations (e.g., fertile vs. subfertile men), BPA urinary concentrations (occupationally vs. nonoccupationally exposed), misclassification of BPA exposure (e.g., using one urine sample to characterize exposure vs. multiple samples), sample sizes, study design (e.g., cross-sectional vs. prospective), and residual confounding (e.g., due to diet and lifestyle factors). It is also possible that some of the statistically significant findings were due to chance alone. Clearly, further studies are needed to further clarify the role of this ubiquitous endocrine-disrupting chemical on male reproductive health.
Nicola Barban, Rick Jansen, Ronald de Vlaming, Ahmad Vaez, Jornt J Mandemakers, Felix C Tropf, Xia Shen, James F Wilson, Daniel I Chasman, Ilja M Nolte, Vinicius Tragante, Sander W van der Laan, John RB Perry, Augustine Kong, Tarunveer S Ahluwalia, Eva Albrecht, Laura Yerges-Armstrong, Gil Atzmon, Kirsi Auro, Kristin Ayers, Andrew Bakshi, Danny Ben-Avraham, Klaus Berger, Aviv Bergman, Lars Bertram, Lawrence F Bielak, Gyda Bjornsdottir, Marc Jan Bonder, Linda Broer, Minh Bui, Caterina Barbieri, Alana Cavadino, Jorge E Chavarro, Constance Turman, Maria Pina Concas, Heather J Cordell, Gail Davies, Peter Eibich, Nicholas Eriksson, Tõnu Esko, Joel Eriksson, Fahimeh Falahi, Janine F Felix, Mark Alan Fontana, Lude Franke, Ilaria Gandin, Audrey J Gaskins, Christian Gieger, Erica P Gunderson, Xiuqing Guo, Caroline Hayward, Chunyan He, Edith Hofer, Hongyan Huang, Peter K Joshi, Stavroula Kanoni, Robert Karlsson, Stefan Kiechl, Annette Kifley, Alexander Kluttig, Peter Kraft, Vasiliki Lagou, Cecile Lecoeur, Jari Lahti, Ruifang Li-Gao, Penelope A Lind, Tian Liu, Enes Makalic, Crysovalanto Mamasoula, Lindsay Matteson, Hamdi Mbarek, Patrick F McArdle, George McMahon, Fleur SW Meddens, Evelin Mihailov, Mike Miller, Stacey A Missmer, Claire Monnereau, Peter J van der Most, Ronny Myhre, Mike A Nalls, Teresa Nutile, Ioanna Panagiota Kalafati, Eleonora Porcu, Inga Prokopenko, Kumar B Rajan, Janet Rich-Edwards, Cornelius A Rietveld, Antonietta Robino, Lynda M Rose, Rico Rueedi, Kathleen A Ryan, Yasaman Saba, Daniel Schmidt, Jennifer A Smith, Lisette Stolk, Elizabeth Streeten, Anke Tönjes, Gudmar Thorleifsson, Sheila Ulivi, Juho Wedenoja, Juergen Wellmann, Peter Willeit, Jie Yao, Loic Yengo, Jing Hua Zhao, Wei Zhao, Daria V Zhernakova, Najaf Amin, Howard Andrews, Beverley Balkau, Nir Barzilai, Sven Bergmann, Ginevra Biino, Hans Bisgaard, Klaus Bønnelykke, Dorret I Boomsma, Julie E Buring, Harry Campbell, Stefania Cappellani, Marina Ciullo, Simon R Cox, Francesco Cucca, Daniela Toniolo, George Davey-Smith, Ian J Deary, George Dedoussis, Panos Deloukas, Cornelia M van Duijn, Eco JC de Geus, Johan G Eriksson, Denis A Evans, Jessica D Faul, Cinzia Felicita Sala, Philippe Froguel, Paolo Gasparini, Giorgia Girotto, Hans-Jörgen Grabe, Karin Halina Greiser, Patrick JF Groenen, Hugoline G de Haan, Johannes Haerting, Tamara B Harris, Andrew C Heath, Kauko Heikkilä, Albert Hofman, Georg Homuth, Elizabeth G Holliday, John Hopper, Elina Hyppönen, Bo Jacobsson, Vincent WV Jaddoe, Magnus Johannesson, Astanand Jugessur, Mika Kähönen, Eero Kajantie, Sharon LR Kardia, Bernard Keavney, Ivana Kolcic, Päivikki Koponen, Peter Kovacs, Florian Kronenberg, Zoltan Kutalik, Martina La Bianca, Genevieve Lachance, William G Iacono, Sandra Lai, Terho Lehtimäki, David C Liewald, Cecilia M Lindgren, Yongmei Liu, Robert Luben, Michael Lucht, Riitta Luoto, Per Magnus, Patrik KE Magnusson, Nicholas G Martin, Matt McGue, Ruth McQuillan, Sarah E Medland, Christa Meisinger, Dan Mellström, Andres Metspalu, Michela Traglia, Lili Milani, Paul Mitchell, Grant W Montgomery, Dennis Mook-Kanamori, Renée de Mutsert, Ellen A Nohr, Claes Ohlsson, Jørn Olsen, Ken K Ong, Lavinia Paternoster, Alison Pattie, Brenda WJH Penninx, Markus Perola, Patricia A Peyser, Mario Pirastu, Ozren Polasek, Chris Power, Jaakko Kaprio, Leslie J Raffel, Katri Räikkönen, Olli Raitakari, Paul M Ridker, Susan M Ring, Kathryn Roll, Igor Rudan, Daniela Ruggiero, Dan Rujescu, Veikko Salomaa, David Schlessinger, Helena Schmidt, Reinhold Schmidt, Nicole Schupf, Johannes Smit, Rossella Sorice, Tim D Spector, John M Starr, Doris Stöckl, Konstantin Strauch, Michael Stumvoll, Morris A Swertz, Unnur Thorsteinsdottir, Roy A Thurik, Nicholas J Timpson, Joyce Y Tung, André G Uitterlinden, Simona Vaccargiu, Jorma Viikari, Veronique Vitart, Henry Völzke, Peter Vollenweider, Dragana Vuckovic, Johannes Waage, Gert G Wagner, Jie Jin Wang, Nicholas J Wareham, David R Weir, Gonneke Willemsen, Johann Willeit, Alan F Wright, Krina T Zondervan, Kari Stefansson, Robert F Krueger, James J Lee, Daniel J Benjamin, David Cesarini, Philipp D Koellinger, Marcel den Hoed, Harold Snieder, and Melinda C Mills. 2016. “Genome-wide analysis identifies 12 loci influencing human reproductive behavior.” Nat Genet, 48, 12, Pp. 1462-1472.Abstract
The genetic architecture of human reproductive behavior-age at first birth (AFB) and number of children ever born (NEB)-has a strong relationship with fitness, human development, infertility and risk of neuropsychiatric disorders. However, very few genetic loci have been identified, and the underlying mechanisms of AFB and NEB are poorly understood. We report a large genome-wide association study of both sexes including 251,151 individuals for AFB and 343,072 individuals for NEB. We identified 12 independent loci that are significantly associated with AFB and/or NEB in a SNP-based genome-wide association study and 4 additional loci associated in a gene-based effort. These loci harbor genes that are likely to have a role, either directly or by affecting non-local gene expression, in human reproduction and infertility, thereby increasing understanding of these complex traits.
Audrey J Gaskins, Janet W Rich-Edwards, Stacey A Missmer, Bernard Rosner, and Jorge E Chavarro. 2016. “In Reply.” Obstet Gynecol, 127, 1, Pp. 162-3.
Yu-Han Chiu, Audrey J Gaskins, Paige L Williams, Jaime Mendiola, Niels Jørgensen, Hagai Levine, Russ Hauser, Shanna H Swan, and Jorge E Chavarro. 2016. “Intake of Fruits and Vegetables with Low-to-Moderate Pesticide Residues Is Positively Associated with Semen-Quality Parameters among Young Healthy Men.” J Nutr, 146, 5, Pp. 1084-92.Abstract
BACKGROUND: Numerous studies have shown that occupational or environmental pesticide exposure can affect male fertility. There is less evidence, however, regarding any potentially adverse effects of pesticide residues in foods on markers of male fertility potential. OBJECTIVES: We examined the relations between fruit and vegetable intake, considering pesticide residue status, and semen quality and serum concentrations of reproductive hormones in healthy young men. METHODS: The Rochester Young Men's Study is a cross-sectional study that recruited men aged 18-22 y (n = 189) in Rochester, New York. Participants completed a questionnaire, provided a semen sample, had a blood sample drawn, and underwent a physical examination at enrollment. Semen samples were analyzed for total sperm count, sperm concentration, morphology, motility, ejaculate volume, total motile count, and total normal count. Dietary intake during the previous year was assessed by a validated food-frequency questionnaire. Fruit and vegetables were categorized as having high [Pesticide Residue Burden Score (PRBS) ≥4] or low-to-moderate (PRBS <4) pesticide residues on the basis of data from the USDA Pesticide Data Program. Linear regression models were used to analyze the associations of fruit and vegetable intake with semen variables and reproductive hormones while adjusting for potential confounding factors. RESULTS: The total intake of fruit and vegetables was unrelated to semen quality. However, the intake of fruit and vegetables with low-to-moderate pesticide residues was associated with a higher total sperm count and sperm concentration, whereas the intake of fruit and vegetables with high pesticide residues was unrelated to semen quality. On average, men in the highest quartile of low-to-moderate-pesticide fruit and vegetable intake (≥2.8 servings/d) had a 169% (95% CI: 45%, 400%) higher total sperm count and a 173% (95% CI: 57%, 375%) higher sperm concentration than did men in the lowest quartile (<1.1 servings/d; P-trend = 0.003 and 0.0005, respectively). The intake of fruit and vegetables, regardless of pesticide-residue status, was not associated with reproductive hormone concentrations. CONCLUSIONS: The consumption of fruit and vegetables with low-to-moderate pesticide residues was positively related to sperm counts in young men unselected by fertility status. This suggests that pesticide residues may modify the beneficial effects of fruit and vegetable intake on semen quality.
Audrey J Gaskins, Yu-Han Chiu, Paige L Williams, Myra G Keller, Thomas L Toth, Russ Hauser, and Jorge E Chavarro. 2016. “Maternal whole grain intake and outcomes of in vitro fertilization.” Fertil Steril, 105, 6, Pp. 1503-1510.e4.Abstract
OBJECTIVE: To evaluate the relationship between pretreatment intake of whole grains and outcomes of IVF. DESIGN: Prospective cohort study. SETTING: Academic medical center. PATIENT(S): A total of 273 women who collectively underwent 438 IVF cycles. INTERVENTION(S): Whole grain intake was assessed with a validated food frequency questionnaire at enrollment. MAIN OUTCOME MEASURE(S): Intermediate and clinical end points of IVF were abstracted from medical records. RESULT(S): Women had a median whole grain intake of 34.2 g per day (∼1.2 servings/day). Higher pretreatment whole grain intake was associated with higher probability of implantation and live birth. The adjusted percentage of cycles resulting in live birth for women in the highest quartile of whole grain intake (>52.4 g/day) was 53% (95% confidence interval [CI] 41%, 65%) compared with 35% (95% CI 25%, 46%) for women in the lowest quartile (<21.4 g/day). This association was largely driven by intake of bran as opposed to germ. When intermediate end points of IVF were examined, only endometrial thickness on the day of ET was associated with whole grain intake. A 28-g per day (∼1 serving/day) increase in whole grain intake was associated with a 0.4-mm (95% CI 0.1, 0.7 mm) increase in endometrial thickness. CONCLUSION(S): Higher pretreatment whole grain intake was related to higher probability of live birth among women undergoing IVF. The higher probability of live birth may result from increased endometrial thickness on the day of ET and improved embryo receptivity manifested in a higher probability of implantation.
Wei Bao, Karin B Michels, Deirdre K Tobias, Shanshan Li, Jorge E Chavarro, Audrey J Gaskins, Allan A Vaag, Frank B Hu, and Cuilin Zhang. 2016. “Parental smoking during pregnancy and the risk of gestational diabetes in the daughter.” Int J Epidemiol, 45, 1, Pp. 160-9.Abstract
BACKGROUND: Fetal exposure to parental smoking may have long-term impact on the development of disease in adulthood. We examined the association of parental smoking during pregnancy with risk of gestational diabetes mellitus (GDM) in the daughter. METHODS: We included 15,665 singleton pregnancies from 10,152 women in the Nurses' Health Study II cohort whose mothers participated in the Nurses' Mothers' Cohort Study. Data on maternal and paternal smoking during pregnancy and associated covariates were recalled by the mothers. GDM diagnosis was self-reported by the daughters and was validated by medical record review in a previous study. We used log-binomial models with generalized estimating equations to estimate relative risks (RRs) and 95% confidence intervals (CIs). RESULTS: We observed a positive association between maternal heavy smoking during pregnancy and risk of GDM in the daughter. The multivariable-adjusted RRs (95% CIs) of GDM among women whose mothers did not smoke during pregnancy, continued smoking 1-14, 15-24, and ≥ 25 cigarettes/day were 1.00 (reference), 1.05 (0.81-1.35), 1.27 (0.95-1.70) and 1.98 (1.18-3.30), respectively (P for trend = 0.01). Further adjustment for the women's perinatal variables, adult-life characteristics and body mass index during various periods of life modestly attenuated the association. No association was observed between paternal smoking during the pregnancy period and risk of GDM in the daughter. CONCLUSIONS: Maternal heavy smoking (≥ 25 cigarettes/day) during pregnancy was associated with higher risk of gestational diabetes in the daughter. Further studies are warranted to confirm our findings and to elucidate the underlying mechanisms.
Audrey J Gaskins, Janet W Rich-Edwards, Paige L Williams, Thomas L Toth, Stacey A Missmer, and Jorge E Chavarro. 2016. “Prepregnancy Low to Moderate Alcohol Intake Is Not Associated with Risk of Spontaneous Abortion or Stillbirth.” J Nutr.Abstract
BACKGROUND: Numerous studies have documented the negative effects of maternal alcohol consumption during pregnancy on risk of pregnancy loss, yet whether prepregnancy alcohol intake affects the risk of spontaneous abortion is still unclear. OBJECTIVE: This study aimed to assess prepregnancy alcohol intake and risk of spontaneous abortion and stillbirth. METHODS: Our prospective cohort study included 27,580 pregnancies reported by 17,929 women in the Nurses' Health Study II between 1990 and 2009. Alcohol intake was assessed in 1989 and 1991 and every 4 y thereafter with the use of a validated questionnaire. Women were classified into 5 categories of consumption: 0, 0.1-1.9, 2-4.9, 5-9.9, and ≥10 g/d (1 serving = ∼12 g). Pregnancies were self-reported, with case pregnancies lost spontaneously (spontaneous abortion after gestation of <20 wk and stillbirth after gestation of ≥20 wk) and comparison pregnancies not ending in fetal loss (live birth, ectopic pregnancy, or induced abortion). Multivariable log-binomial regression models with generalized estimating equations were used to estimate RRs and 95% CIs. RESULTS: Incident spontaneous abortion and stillbirth were reported in 4326 (15.7%) and 205 (0.7%) pregnancies, respectively. Prepregnancy alcohol intake was not associated with spontaneous abortion. Compared with women who did not consume alcohol, the multivariable RRs (95% CIs) for increasing categories of alcohol intake among women who did consume alcohol were 1.04 (0.97, 1.12) for 0.1-1.9 g/d, 1.02 (0.94, 1.11) for 2-4.9 g/d, 1.01 (0.92, 1.10) for 5-9.9 g/d, and 0.98 (0.88, 1.09) for ≥10 g/d (P-trend = 0.45). Women who consumed ≥2 servings beer/wk before pregnancy had a 9% (95% CI: 1%, 17%) lower risk of spontaneous abortion than did women who consumed <1 serving beer/mo; however, this association did not persist in various sensitivity analyses. Prepregnancy consumption of wine and liquor were not associated with spontaneous abortion. Total alcohol and specific alcohol beverage intake before pregnancy were not associated with stillbirth. CONCLUSION: Prepregnancy alcohol intake was not related to risk of incident spontaneous abortion or stillbirth in women with no history of pregnancy loss. Our results provide reassuring evidence that low to moderate alcohol intake (≤12 g/d) before pregnancy initiation does not affect risk of pregnancy loss.
J Prescott, LV Farland, DK Tobias, AJ Gaskins, D Spiegelman, JE Chavarro, JW Rich-Edwards, RL Barbieri, and SA Missmer. 2016. “A prospective cohort study of endometriosis and subsequent risk of infertility.” Hum Reprod, 31, 7, Pp. 1475-82.Abstract
STUDY QUESTION: Is there a temporal relationship between endometriosis and infertility? SUMMARY ANSWER: Endometriosis is associated with a higher risk of subsequent infertility, but only among women age <35 years. WHAT IS KNOWN ALREADY: Endometriosis is the most commonly observed gynecologic pathology among infertile women undergoing laparoscopic examination. Whether endometriosis is a cause of infertility or an incidental discovery during the infertility examination is unknown. STUDY DESIGN, SIZE, DURATION: This study included data collected from 58 427 married premenopausal female nurses <40 years of age from 1989 to 2005, who are participants of the Nurses' Health Study II prospective cohort. PARTICIPANTS/MATERIALS, SETTING, METHODS: Our exposure was laparoscopically confirmed endometriosis. Multivariate Cox proportional hazards regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for infertility risk (defined as attempting to conceive for >12 months) among women with and without endometriosis. MAIN RESULTS AND THE ROLE OF CHANCE: We identified 4612 incident cases of infertility due to any cause over 362 219 person-years of follow-up. Compared with women without a history of endometriosis, women with endometriosis had an age-adjusted 2-fold increased risk of incident infertility (HR = 2.12, 95% CI = 1.76-2.56) that attenuated slightly after accounting for parity. The relationship with endometriosis was only observed among women <35 years of age (multivariate HR <35 years = 1.77, 95% CI = 1.46-2.14; multivariate HR 35-39 years = 1.20, 95% CI = 0.94-1.53; P-interaction = 0.008). Risk of primary versus secondary infertility was similar subsequent to endometriosis diagnosis. Among women with primary infertility, 50% became parous after the endometriosis diagnosis, and among all women with endometriosis, 83% were parous by age 40 years. LIMITATIONS, REASONS FOR CAUTION: We did not have information on participants' intentions to conceive, but by restricting the analytic population to married women we increased the likelihood that pregnancies were planned (and therefore infertility would be recognized). Women in our cohort with undiagnosed asymptomatic endometriosis will be misclassified as unexposed. However, the small proportion of these women are diluted among the >50 000 women accurately classified as endometriosis-free, minimizing the impact of exposure misclassification on the effect estimates. WIDER IMPLICATIONS OF THE FINDINGS: This study supports a temporal association between endometriosis and infertility risk. Our prospective analysis indicates a possible detection bias in previous studies, with our findings suggesting that the infertility risk posed by endometriosis is about half the estimates observed in cross-sectional analyses. STUDY FUNDING/COMPETING INTERESTS: This work was supported by the National Institutes of Health (grant numbers: UM1 CA176726, HD52473, HD57210, T32DK007703, T32HD060454, K01DK103720). We have no competing interests to declare.
Laura Abadia, Audrey J Gaskins, Yu-Han Chiu, Paige L Williams, Myra Keller, Diane L Wright, Irene Souter, Russ Hauser, and Jorge E Chavarro. 2016. “Serum 25-hydroxyvitamin D concentrations and treatment outcomes of women undergoing assisted reproduction.” Am J Clin Nutr, 104, 3, Pp. 729-35.Abstract
BACKGROUND: Vitamin D deficiency impairs fertility in animal models, but the role of vitamin D in human fertility or treatment of infertility is less clear. OBJECTIVE: We examined the association between circulating 25-hydroxyvitamin D [25(OH)D] concentrations and the outcome in women undergoing assisted reproduction technologies (ARTs). DESIGN: We randomly selected 100 women undergoing infertility treatment with ART enrolled in an ongoing prospective cohort study who underwent 168 treatment cycles. Serum 25(OH)D concentrations were measured in samples collected from women between days 3 and 9 of gonadotropin treatment. Generalized linear mixed models were used to evaluate the association of 25(OH)D concentrations with ART outcomes while adjusting for potential confounders and accounting for repeated treatment cycles per woman. RESULTS: Median (range) serum 25(OH)D concentrations were 86.5 (33.5-155.5) nmol/L. Ninety-one percent of participants consumed multivitamins. Serum 25(OH)D concentrations were positively related to fertilization rate. The adjusted fertilization rate for women in increasing quartiles of serum 25(OH)D were 0.62 (95% CI: 0.51, 0.72), 0.53 (95% CI: 0.43, 0.63), 0.67 (95% CI: 0.56, 0.76), and 0.73 (95% CI: 0.63, 0.80), respectively (P-trend = 0.03). This association persisted when analyses were restricted to women with serum 25(OH)D between 50 and 125 nmol/L when models were further adjusted for season of blood draw and when analyses were restricted to the first treatment cycle. However, 25(OH)D concentrations were unrelated to probability of pregnancy (P-trend = 0.83) or live birth after ART (P-trend = 0.47). CONCLUSION: Vitamin D may be associated with higher fertilization rates, but this apparent benefit does not translate into higher probability of pregnancy or live birth. This trial was registered at www.clinicaltrials.gov as NCT00011713.
Jorge E Chavarro, Lidia Mínguez-Alarcón, Yu-Han Chiu, Audrey J Gaskins, Irene Souter, Paige L Williams, Antonia M Calafat, and Russ Hauser. 2016. “Soy Intake Modifies the Relation Between Urinary Bisphenol A Concentrations and Pregnancy Outcomes Among Women Undergoing Assisted Reproduction.” J Clin Endocrinol Metab, 101, 3, Pp. 1082-90.Abstract
CONTEXT: Experimental data in rodents suggest that the adverse reproductive health effects of bisphenol A (BPA) can be modified by intake of soy phytoestrogens. Whether the same is true in humans is not known. OBJECTIVE: The purpose of this study was to evaluate whether soy consumption modifies the relation between urinary BPA levels and infertility treatment outcomes among women undergoing assisted reproduction. SETTING: The study was conducted in a fertility center in a teaching hospital. DESIGN: We evaluated 239 women enrolled between 2007 and 2012 in the Environment and Reproductive Health (EARTH) Study, a prospective cohort study, who underwent 347 in vitro fertilization (IVF) cycles. Participants completed a baseline questionnaire and provided up to 2 urine samples in each treatment cycle before oocyte retrieval. IVF outcomes were abstracted from electronic medical records. We used generalized linear mixed models with interaction terms to evaluate whether the association between urinary BPA concentrations and IVF outcomes was modified by soy intake. MAIN OUTCOME MEASURE: Live birth rates per initiated treatment cycle were measured. RESULTS: Soy food consumption modified the association of urinary BPA concentration with live birth rates (P for interaction = .01). Among women who did not consume soy foods, the adjusted live birth rates per initiated cycle in increasing quartiles of cycle-specific urinary BPA concentrations were 54%, 35%, 31%, and 17% (P for trend = .03). The corresponding live birth rates among women reporting pretreatment consumption of soy foods were 38%, 42%, 47%, and 49% (P for trend = 0.35). A similar pattern was found for implantation (P for interaction = .02) and clinical pregnancy rates (P for interaction = .03) per initiated cycle, where urinary BPA was inversely related to these outcomes among women not consuming soy foods but unrelated to them among soy consumers. CONCLUSION: Soy food intake may protect against the adverse reproductive effects of BPA. As these findings represent the first report suggesting a potential interaction between soy and BPA in humans, they should be further evaluated in other populations.
Russ Hauser, Audrey J Gaskins, Irene Souter, Kristen W Smith, Laura E Dodge, Shelley Ehrlich, John D Meeker, Antonia M Calafat, and Paige L Williams. 2016. “Urinary Phthalate Metabolite Concentrations and Reproductive Outcomes among Women Undergoing in Vitro Fertilization: Results from the EARTH Study.” Environ Health Perspect, 124, 6, Pp. 831-9.Abstract
BACKGROUND: Evidence from both animal and human studies suggests that exposure to phthalates may be associated with adverse female reproductive outcomes. OBJECTIVE: We evaluated the associations between urinary concentrations of phthalate metabolites and outcomes of assisted reproductive technologies (ART). METHODS: This analysis included 256 women enrolled in the Environment and Reproductive Health (EARTH) prospective cohort study (2004-2012) who provided one to two urine samples per cycle before oocyte retrieval. We measured 11 urinary phthalate metabolites [mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), mono-isobutyl phthalate (MiBP), mono-n-butyl phthalate (MBP), monobenzyl phthalate (MBzP), monoethyl phthalate (MEP), monocarboxyisooctyl phthalate (MCOP), monocarboxyisononyl phthalate (MCNP), and mono(3-carboxypropyl) phthalate (MCPP)]. We used generalized linear mixed models to evaluate the association of urinary phthalate metabolites with in vitro fertilization (IVF) outcomes, accounting for multiple IVF cycles per woman. RESULTS: In multivariate models, women in the highest as compared with lowest quartile of MEHP, MEHHP, MEOHP, MECPP, ΣDEHP (MEHP + MEHHP + MEOHP + MECPP), and MCNP had lower oocyte yield. Similarly, the number of mature (MII) oocytes retrieved was lower in the highest versus lowest quartile for these same phthalate metabolites. The adjusted differences (95% CI) in proportion of cycles resulting in clinical pregnancy and live birth between women in the fourth versus first quartile of ΣDEHP were -0.19 (-0.29, -0.08) and -0.19 (-0.28, -0.08), respectively, and there was also a lower proportion of cycles resulting in clinical pregnancy and live birth for individual DEHP metabolites. CONCLUSIONS: Urinary concentrations of DEHP metabolites were inversely associated with oocyte yield, clinical pregnancy, and live birth following ART. CITATION: Hauser R, Gaskins AJ, Souter I, Smith KW, Dodge LE, Ehrlich S, Meeker JD, Calafat AM, Williams PL, for the EARTH Study Team. 2016. Urinary phthalate metabolite concentrations and reproductive outcomes among women undergoing in vitro fertilization: results from the EARTH study. Environ Health Perspect 124:831-839; http://dx.doi.org/10.1289/ehp.1509760.
Carmen Messerlian, Irene Souter, Audrey J Gaskins, Paige L Williams, Jennifer B Ford, Yu-Han Chiu, Antonia M Calafat, and Russ Hauser. 2016. “Urinary phthalate metabolites and ovarian reserve among women seeking infertility care.” Hum Reprod, 31, 1, Pp. 75-83.Abstract
STUDY QUESTION: Are urinary phthalate metabolites associated with reduced antral follicle growth among women in an infertility setting? SUMMARY ANSWER: Higher urinary concentrations of di(2-ethylhexyl) phthalate (DEHP) metabolites were associated with significant decreases in antral follicle count (AFC) among women seeking infertility care. WHAT IS KNOWN ALREADY: Experimental animal studies show that DEHP accelerates primordial follicle recruitment and inhibits antral follicle growth. Whether phthalates also reduce the growing antral follicle pool in humans remains unknown. STUDY DESIGN, SIZE, DURATION: We examined the association between urinary phthalate metabolites and AFC using prospective data from 215 females recruited between 2004 and 2012 in the Environment and Reproductive Health (EARTH) study. PARTICIPANTS/MATERIALS, SETTING, METHODS: We quantified the urinary concentrations of 11 phthalate metabolites. We estimated the geometric mean for all urine samples provided prior to unstimulated day 3 AFC assessment for each woman. We evaluated the association of AFC with ∑DEHP (molar sum of four DEHP metabolites) and individual phthalate metabolites using Poisson regression, adjusting for age, BMI and smoking. MAIN RESULTS AND THE ROLE OF CHANCE: We observed significant decreases in mean AFC for all higher quartiles of ∑DEHP as compared with the lowest quartile. Compared with women in the first quartile of ∑DEHP, women in the second, third and fourth quartiles had a -24% (95% confidence interval (CI): -32%, -16%), -19% (95% CI: -27%, -9%), and -14% (95% CI: -23%, -5%) decrease in mean AFC. The absolute mean AFC in the first quartile was 14.2 follicles (95% CI: 13.2, 15.2) compared with 10.7 follicles (95% CI: 9.9, 11.6) in the second quartile. We observed similar trends among the four individual DEHP metabolites. There was no consistent change in AFC among the remaining phthalate metabolite concentrations evaluated. LIMITATIONS, REASONS FOR CAUTION: We demonstrated a negative association between DEHP and a well-established marker of ovarian reserve among a subfertile population. However these findings may not be generalizable to women without fertility concerns, and we cannot rule out co-exposure to other chemicals. WIDER IMPLICATIONS OF THE FINDINGS: Environmental chemicals that inhibit the size of the growing antral follicle pool can impair fertility and reduce fecundity. This study suggests evidence in need of further investigation on the impact of phthalates on the human oocyte and follicular development. STUDY FUNDING/COMPETING INTERESTS: Work supported by grants ES009718, ES022955, ES000002, and T32ES007069 from the National Institute of Environmental Health Sciences (NIEHS) and grant T32 DK007703-16 from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). C.M. was supported by a post-doctoral training award from the Canadian Institutes of Health Research. There are no competing interests to declare.
2015
Audrey J Gaskins, Yu-Han Chiu, Paige L Williams, Jennifer B Ford, Thomas L Toth, Russ Hauser, and Jorge E Chavarro. 2015. “Association between serum folate and vitamin B-12 and outcomes of assisted reproductive technologies.” Am J Clin Nutr, 102, 4, Pp. 943-50.Abstract
BACKGROUND: Preconceptional folate and vitamin B-12 have been linked to beneficial reproductive outcomes in both natural pregnancies and those after assisted reproductive technology (ART) treatment. OBJECTIVE: The objective of the study was to evaluate the associations of serum folate and vitamin B-12 with ART outcomes. DESIGN: This analysis included a random sample of 100 women (154 ART cycles) participating in a prospective cohort study [Environment and Reproductive Health (EARTH)] at the Massachusetts General Hospital Fertility Center (2007-2013). Serum folate and vitamin B-12 were measured in blood samples collected between days 3 and 9 of treatment. Generalized estimating equations with adjustment for age, BMI, and race were used to evaluate the association of serum folate and vitamin B-12 with ART outcomes. RESULTS: Women in the highest quartile of serum folate (>26.3 ng/mL) had 1.62 (95% CI: 0.99, 2.65) times the probability of live birth compared with women in the lowest quartile (<16.6 ng/mL). Women in the highest quartile of serum vitamin B-12 (>701 pg/mL) had 2.04 (95% CI: 1.14, 3.62) times the probability of live birth compared with women in the lowest quartile (<439 pg/mL). Suggestive evidence of an interaction was observed; women with serum folate and vitamin B-12 concentrations greater than the median had 1.92 (95% CI: 1.12, 3.29) times the probability of live birth compared with women with folate and vitamin B-12 concentrations less than or equal to the median. This translated into an adjusted difference in live birth rates of 26% (95% CI: 10%, 48%; P = 0.02). CONCLUSION: Higher serum concentrations of folate and vitamin B-12 before ART treatment were associated with higher live birth rates among a population exposed to folic acid fortification. This trial was registered at clinicaltrials.gov as NCT00011713.
Audrey J Gaskins, Janet W Rich-Edwards, Stacey A Missmer, Bernard Rosner, and Jorge E Chavarro. 2015. “Association of Fecundity With Changes in Adult Female Weight.” Obstet Gynecol, 126, 4, Pp. 850-8.Abstract
OBJECTIVE: To evaluate whether weight change since age 18 years, current body mass index (BMI), and BMI at age 18 years are associated with fecundity. METHODS: Our study included 1,950 women in the Nurses' Health Study 3 (2010-2014), a prospective cohort study, currently attempting pregnancy. Height, current weight, and weight at age 18 years were self-reported on the baseline questionnaire. Every 3-6 months thereafter, women reported the current duration of their pregnancy attempt. Multivariable-accelerated failure time models were used to estimate the time ratios and 95% confidence intervals (CIs). RESULTS: For every 5-kg increase in body weight from age 18 years, current duration of pregnancy attempt increased by 5% (95% CI 3-7%). Compared with women who maintained weight, the adjusted median current duration was 0.5 months shorter in those who lost weight, 0.3 months longer for those who gained 4-9.9 kg and 10-19.9 kg, and 1.4 months longer for those who gained 20 kg or more (P trend ≤.001). The adjusted time ratio (95% CI) for a 5-kg/m increase in current BMI was 1.08 (1.04-1.12). After multivariable adjustment (including adjustment for current BMI), being underweight at age 18 years (BMI less than 18.5) was associated with a longer current duration of pregnancy attempt compared with normal-weight women (time ratio 1.25, 95% CI 1.07-1.47); however, being overweight or obese at age 18 years was not associated with fecundity. CONCLUSION: Gaining weight in adulthood, being overweight or obese in adulthood, and being underweight at age 18 years were associated with a modest reduction in fecundity. LEVEL OF EVIDENCE: II.
Aaron K Styer, Audrey J Gaskins, Paula C Brady, Patrick M Sluss, Jorge E Chavarro, Russ B Hauser, and Thomas L Toth. 2015. “Dynamic antimüllerian hormone levels during controlled ovarian hyperstimulation predict in vitro fertilization response and pregnancy outcomes.” Fertil Steril, 104, 5, Pp. 1153-61.e1-7.Abstract
OBJECTIVE: To evaluate the patterns of change in serum antimüllerian hormone (AMH) during controlled ovarian hyperstimulation (COH) and their relation to concurrent response and in vitro fertilization (IVF) pregnancy outcomes. DESIGN: Prospective cohort study. SETTING: Academic medical center. PATIENT(S): A total of 113 consecutive fresh IVF embryo transfer cycles from September 1, 2012 through January 1, 2013. INTERVENTION(S): Serial serum AMH measurements were analyzed on each day that serum estradiol (E2) was drawn during COH. MAIN OUTCOME MEASURE(S): Relationship between the rate of COH AMH change [Δ ng/mL per day] (stratified into tertiles), and ovarian response, and pregnancy outcomes. RESULT(S): During COH, AMH declined. Age and ovarian reserve testing were associated with the rate of AMH decline (RAD). Women with intermediate and minimal RAD had statistically significantly fewer follicles ≥ 12 mm, lower peak serum E2, fewer oocytes, and inferior early embryo development compared with women with the greatest RAD. Compared with patients with the lowest RAD, clinical pregnancy was more likely in patients with the greatest RAD in the total population (adjusted odds ratio 3.51; 95% confidence interval, 1.03, 11.94) and among patients older than 35 years (adjusted odds ratio 6.95; 95% confidence interval, 1.09, 44.1). CONCLUSION(S): The rate of COH AMH decline was associated with ovarian reserve testing, oocyte yield, embryo progression, and clinical pregnancy rates, particularly in women older than 35 years. These results suggest that dynamic AMH levels may provide a novel intracycle approach to predict response and treatment outcomes after IVF.
YH Chiu, MC Afeiche, AJ Gaskins, PL Williams, JC Petrozza, C Tanrikut, R Hauser, and JE Chavarro. 2015. “Fruit and vegetable intake and their pesticide residues in relation to semen quality among men from a fertility clinic.” Hum Reprod, 30, 6, Pp. 1342-51.Abstract
STUDY QUESTION: Is consumption of fruits and vegetables with high levels of pesticide residues associated with lower semen quality? SUMMARY ANSWER: Consumption of fruits and vegetables with high levels of pesticide residues was associated with a lower total sperm count and a lower percentage of morphologically normal sperm among men presenting to a fertility clinic. WHAT IS KNOWN ALREADY: Occupational and environmental exposure to pesticides is associated with lower semen quality. Whether the same is true for exposure through diet is unknown. STUDY DESIGN, SIZE, DURATION: Men enrolled in the Environment and Reproductive Health (EARTH) Study, an ongoing prospective cohort at an academic medical fertility center. Male partners (n = 155) in subfertile couples provided 338 semen samples during 2007-2012. PARTICIPANTS/MATERIALS, SETTING, METHODS: Semen samples were collected over an 18-month period following diet assessment. Sperm concentration and motility were evaluated by computer-aided semen analysis (CASA). Fruits and vegetables were categorized as containing high or low-to-moderate pesticide residues based on data from the annual United States Department of Agriculture Pesticide Data Program. Linear mixed models were used to analyze the association of fruit and vegetable intake with sperm parameters accounting for within-person correlations across repeat samples while adjusting for potential confounders. MAIN RESULTS AND THE ROLE OF CHANCE: Total fruit and vegetable intake was unrelated to semen quality parameters. High pesticide residue fruit and vegetable intake, however, was associated with poorer semen quality. On average, men in highest quartile of high pesticide residue fruit and vegetable intake (≥1.5 servings/day) had 49% (95% confidence interval (CI): 31%, 63%) lower total sperm count and 32% (95% CI: 7%, 58%) lower percentage of morphologically normal sperm than men in the lowest quartile of intake (<0.5 servings/day) (P, trend = 0.003 and 0.02, respectively). Low-to-moderate pesticide residue fruit and vegetable intake was associated with a higher percentage of morphologically normal sperm (P, trend = 0.04). LIMITATIONS, REASONS FOR CAUTION: Surveillance data, rather than individual pesticide assessment, was used to assess the pesticide residue status of fruits and vegetables. CASA is a useful method for clinical evaluation but may be considered less favorable for accurate semen analysis in the research setting. Owing to the observational nature of the study, confirmation is required by interventional studies as well. WIDER IMPLICATIONS OF THE FINDINGS: To our knowledge, this is the first report on the consumption of fruits and vegetables with high levels of pesticide residue in relation to semen quality. Further confirmation of these findings is warranted. STUDY FUNDING/COMPETING INTERESTS: Supported by National Institutes of Health grants ES009718, ES022955, ES000002, P30 DK046200 and Ruth L. Kirschstein National Research Service Award T32 DK007703-16. None of the authors has any conflicts of interest to declare.
Deirdre K Tobias, Audrey J Gaskins, Stacey A Missmer, Frank B Hu, Joann E Manson, Germaine M Buck Louis, Cuilin Zhang, and Jorge E Chavarro. 2015. “History of infertility and risk of type 2 diabetes mellitus: a prospective cohort study.” Diabetologia, 58, 4, Pp. 707-15.Abstract
AIMS/HYPOTHESIS: We sought to evaluate the relationship between delayed conception and type 2 diabetes risk, given that there are plausible underlying mechanisms linking the two, including inflammation and insulin resistance. METHODS: Participants of the Nurses' Health Study II prospective cohort were included if they were free of chronic disease (cardiovascular disease, type 2 diabetes, cancer) at baseline. Biennial questionnaires updated information on infertility status (>12 months attempted pregnancy), lifestyle characteristics and several health-related outcomes. Self-reported cases of diabetes were confirmed using a follow-up questionnaire. Multivariable Cox proportional hazards models were used to compute the HRs and 95% CIs. RESULTS: Incident type 2 diabetes occurred in 5,993 of the 112,106 participants over 24 years of follow-up (1989-2013). A history of infertility was reported in 27,774 (24.8%) women and was associated with a 20% greater risk of developing diabetes, compared with those never reporting infertility (HR 1.20 [95% CI 1.14, 1.28]), after adjusting for age, lifestyle factors, marital status, oral contraceptive use, family history of diabetes and BMI. Compared with women without a history of infertility, the causes of infertility associated with a higher diabetes risk were ovulation disorders (HR 1.43 [95% CI 1.29, 1.58]) and tubal factor (HR 1.34 [95% CI 1.13, 1.58]). Cervical factor (HR 1.06 [95% CI 0.81, 1.40]) and endometriosis (HR 1.06 [95% CI 0.89, 1.27]) were not associated, while male factor infertility was associated with a modestly higher diabetes risk (HR 1.15 [95% CI 1.00, 1.33]). CONCLUSIONS/INTERPRETATION: These novel findings suggest a history of infertility, particularly that related to ovulation disorders and tubal blockage, is significantly associated with a higher risk of type 2 diabetes.
Wei Xia, Yu-Han Chiu, Paige L Williams, Audrey J Gaskins, Thomas L Toth, Cigdem Tanrikut, Russ Hauser, and Jorge E Chavarro. 2015. “Men's meat intake and treatment outcomes among couples undergoing assisted reproduction.” Fertil Steril, 104, 4, Pp. 972-979.Abstract
OBJECTIVE: To study the relationship between men's meat intake and clinical outcomes in couples undergoing infertility treatment with the use of assisted reproductive technology (ART). DESIGN: Prospective cohort study. SETTING: Fertility center. PATIENT(S): A total of 141 men whose female partners underwent 246 ART cycles from 2007 to 2014. INTERVENTION(S): None. Total and specific types of meat intake were estimated from dietary questionnaires. MAIN OUTCOME MEASURE(S): Fertilization, implantation, clinical pregnancy, and live-birth rates per initiated cycle. Mixed-effects models account for multiple IVF cycles per woman. RESULT(S): There was a positive association between poultry intake and fertilization rate, with a 13% higher fertilization rate among men in the highest quartile of poultry intake compared with those in the lowest quartile (78% vs. 65%). Processed meat intake was inversely related to fertilization rate in conventional IVF cycles but not in IVF cycles using intracytoplasmic sperm injection. The adjusted fertilization rates for men in increasing quartiles of processed meat intake were 82%, 67%, 70%, and 54% in conventional IVF cycles. Men's total meat intake, including intake of specific types of meat, was not associated with implantation, clinical pregnancy, or live-birth rates. CONCLUSION(S): Poultry intake was positively associated with fertilization rates, whereas processed meat intake was negatively associated with fertilization rates among couples undergoing conventional IVF. This, however, did not translate into associations with clinical pregnancy or live-birth rates.
Audrey Jane Gaskins, Jaime Mendiola, Myriam Afeiche, Niels Jørgensen, Shanna H Swan, and Jorge E Chavarro. 2015. “Physical activity and television watching in relation to semen quality in young men.” Br J Sports Med, 49, 4, Pp. 265-70.Abstract
BACKGROUND: Semen quality appears to have declined over the past decades but reasons for this decline are unresolved. The concurrent increase in sedentary behaviour may be a contributing factor. The objective of this study was to evaluate the relationship of physical activity and television (TV) watching with sperm parameters in a population of young, healthy men. METHODS: Men aged 18-22 years (n=189) from the Rochester Young Men's Study (2009-2010) participated in this analysis. Physical activity (h/week of moderate and vigorous exercise) and TV watching (h/week of TV, video or DVD watching) over the past 3 months were assessed via questionnaire. Semen quality was assessed by sperm concentration, motility, morphology and total sperm count. RESULTS: Sperm concentration and total sperm count were directly related to physical activity after multivariable adjustment (p-trend=0.01 and 0.04); men in the highest quartile of moderate-to-vigorous activity (≥15 h/week) had 73% (95% CI 15% to 160%) higher sperm concentration than men in the lowest quartile (<5 h/week). TV watching was inversely associated with sperm concentration and total sperm count in multivariable analyses (p-trend=0.05 and 0.06); men in the highest quartile of TV watching (>20 h/week) had 44% (95% CI 15 to 63%) lower sperm concentration than men in the lowest quartile (0 h/week). These measures of physical and leisure time activities were not significantly associated with sperm motility or morphology. CONCLUSIONS: In this population of healthy men, higher moderate-to-vigorous activity and less TV watching were significantly associated with higher total sperm count and sperm concentration.
Audrey J Gaskins, Thomas L Toth, and Jorge E Chavarro. 2015. “Prepregnancy Nutrition and Early Pregnancy Outcomes.” Curr Nutr Rep, 4, 3, Pp. 265-272.Abstract
Implantation failure and pregnancy loss are estimated to affect up to 75% of fertilized ova; however as of yet there is limited empirical evidence, particularly at the population level, for understanding the environmental determinants of these losses. The purpose of this review is to summarize the current knowledge on prepregnancy nutrition and early pregnancy outcomes with particular focus on the outcome of spontaneous abortion among pregnancies conceived naturally and early pregnancy end points among pregnancies conceived through fertilization. To date, there is limited evidence to support associations of prepregnancy vitamin D and caffeine intake with pregnancy loss. There is suggestive data supporting a link between a healthy diet and lower risk of pregnancy loss. High folate and minimal to no alcohol intake prior to conception have the most consistent evidence supporting an association with lower risk of pregnancy loss.

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